Pyrophoric alloys without iron



O r I F Umtedltftes atent PYROPHORIC ALLOYS WITHOUT IRON Walter Bungardt, Essen-Bredeney, Germany, assignor to ,Ronson Metals Corporation, Newark, NJ.

No Drawing. Filed Jan. 31, 1958, Ser. No. 712,307 Claims priority, application Germany Feb. 8, 1957 2 "(Cl. 75-152) This invention refers to the manufacture of pyrophoric mass in rod and like formation for use in connection with lighters, safety lamps and for other industrial purposes.

It is well'known that alloys containing 'crium-misch metal with zinc when cast, may-be employed for pyrophoric purposes, for example, as flints in safety lamps to be operated by miners as well as in the mining industry. Alloys of this type were heretofore manufactured exclusively by casting.

However; the operational manufacturing conditions and the finished .flint rod thereby obtained did not comply with economical and practical requirements, so that all attempts to make use of aforesaid alloy failed.

New attempts have shown that a most economical and safe process can be carried out by means of extrusion if ingots of alloys of the aforesaid type of predetermined composition are subjected to such special process. It has now been surprisingly found that very desirable practical requirements can be realized and fulfilled and that none of the heretofore encountered difiiculties will occur, if alloys are selected which are composed of cerium-misch metal with additions of zinc of predetermined range from 5% up to 25% by weight of the total alloy and more specifically from 12% to 17% by weight.

It is therefore one of the primary objects of the invention to provide means afiording the manufacture of flint rods and like shapes of pyrophoric material with improved sparking and other desirable properties, thereby contributing to increased and varied technically useful alloys.

- it is another object of the present invention to provide means conducive to an economical and continuous novel process for obtaining finished extruded flint shapes in substantially completely devoid of iron, additional elements are incorporated, such as copper, cadmium, antimony, bismuth and manganese, ranging within certain limits from .5% to 8% by weight and preferably between 2% to 6% by weight.

Furthermore, other additions such as magnesium, have been found to be of great advantage in making up the alloy for the ingot to be subjected to extrusion, the magnesium amounting to about .5 to 5% by weight, from which in particular dense spark formation will result.

It is therefore still another object of the present invention to provide means rendering the possibility of influ encing crystal formation in the finished flint product, so that on the one hand, the pyrophoric metal will oiier great resistance to corrosion and wear during normal use, while on the other hand, its sparking and pyrophoric eiiect will be considerably increased and may be controlled within a relatively large range.

The invention will be more fully and comprehensively ice understood from a consideration of the following detailed description with the understanding, that the improvement is capable of extended application and is not confined to the precise disclosure, suggested changes and modifications may be made herein which do not affect the spirit of the invention nor exceed the scope thereof as expressed in the appended claims.

The following examples demonstrate the mode and preferred compounds according to which the present invention may be carried into effect.

Example I about 2% by weight of cadmium and about 1.5% of copper, with the remainder cerium-misch metal of commercial purity, is melted and made-up into ingots cast at about.150 to 500 C. After cooling down such ingot may then be subjected to extrusion at'a temperature ranging from 380 C. to 400 C; The extrusion pressure applied amounts to about 4,100 kg./cm.

Example II -An alloy containing I cadmium, approximately 2% of manganese and about 1.5 by weight of copper, is obtained having as a remaining constituent cerium-misch metal of commercial purity. Such alloy is converted into an ingot at about to 500 C. and after cooling down may then be subjected to extrusion at an extrusion temperature of 380 to 400 C. with an applied extrusion pressure of about 4,200 kg./cm.

Example III Example IV An alloy is made up containing about 15% by weight of zinc, about 3% by weight of cadmium, about 2% by weight of antimony and 1.5% by weight by copper, the remainder being cerium-misch metal of commercial purity. This alloy is cast into suitably sized ingots at a temperature of 150 to 500 C. and after cooling down the ingot may then be subjected to extrusion at 380 to 400 C. at a pressure of about 4,400 kg./c'm.

Example V An alloy is employed consisting of about 15% by weight of zinc, about 3% by weight of cadmium, about 2% by weight of bismuth with approximately 1.5% by weight of copper, the remainder being cerium-misch metal of commercial purity. The alloy is melted and then cast into ingots at 150 to 500 C. and may thereafter be extruded at 380 to 400 C. at an extrusion pressure of about 4,500 kg./cm.

The aforesaid cerium (misch metal)-zinc alloys may contain between 14% and 16% by weight of zinc and between 2% and 4% by weight of cadmium, with the addition of trace amounts of copper of about 1.5 by weight.

It ensues from the aforesaid examples that the extrusion pressure may be easily regulated by certain additions of manganese, preferably ranging between .5% to 8% by weight and preferably ranging from 2% to 6% about 14% of zinc, about 4% of by weight. A further increase of the extrusion pressure was obtainable through the addition of magnesium ranging between .5% to 5% byweight. A particularly usefulalloy. havingan add .tion of magnesium of approximately 2.5% by weight requires a considerably increased extrusion pressure. Other additions to regulate the extrusion pressure may be additions of antimony of 2% by weight or bismuth of about 2% by weight, in the latter cases, the extrusion pressure being markedly reduced in comparison with the extrusion pressure'obtained when magnesium was added to the basic constituents of cerium (misch metal) -zinc-cadmiurn.-copper alloy.

It has been found thatthe extrusion process may be advantageously carried out at a required extrusion pressure ranging from about 4,000 kg./cm. to about less than 5,000 kgJcrn, To this end an ingot is produced by adding to cerium (misch metal) a zinc content ranging between 5% and 25% byweight with the additions of at least one of theelements selected from the group comprising copper, m-agnesinm, cadmlum, antimony, bismuth and manganese;

Although preferred embodiments of the invention have been described, it will be understood that modifications may be made within the spirit and scope of the appended clams. It will, however, be understood that there is no intention to include unmentioned ingredients other than minor impurities.

Having thus described the invention, What is claimed as new and. desired to. be secured by-Letters. Patent, is: 1. A pyrophoric mass suitable for extrusion to produce finished flints, in rod formation; consisting essentially of cerium (misch metal) with zinc ranging from 5% to 25% by weight, and having an addition of at least one of the elements selected fromthegroup consisting of copper, cadmium, antimony, bismuth and manganese, said addition ranging from 2% to 6% by weight, and a further addition. of magnesium, amounting to about-.5%3 to 5% by weight-"to adjust the. extrusionpressure to at least 4,100 kg./cm. the balancebeing cerium (misch metal). 2. A'pyrophoric mass suitable for extrusion to pro ducefinished 'flints in-rod formation; consistingessentially of cerium (misch metal) with zinc. of, about 14% by weight, and further additions of copper, manganese and cadmium, the amount of copper being about 1.5% by weight, that. of manganese being about 2%. by weight, and that of cadmium being about 4% by. weight.

References Cited in the file of-this patent UNITED, STATES PATENTS Great.- Britain:. Nov.v 14,, 1912- 

1. A PYROPHORIC MASS SUITABLE FOR EXTRUSION TO PRODUCE FINISHED FLINTS IN ROD FORMATION; CONSISTING ESSENTIALLY OF CERIUM (MISCH METAL) WITH ZINC RANGING FROM 5% TO 25% BY WEIGHT, AND HAVING AN ADDITION OF AT LEAST ONE OF THE ELEMENTS SELECTED FROM THE GROUP CONSISTING OF COPPER, CADMIUM, ANTIMONY, BISMUTH AND MANGANESE, SAID ADDITION RANGING FROM 2% TO 6% BY WEIGHT, AND A FURTHER ADDITION OF MANGNESIUM AMOUNTING TO ABOUT .5% TO 5% BY WEIGHT TO ADJUST THE EXTRUSION PRESSURE TO AT LEAST 4,100 KG./CM.2, THE BALANCE BEING CERIUM (MISCH METAL). 